title: Liver glycogenosis caused by a defective phosphorylase system: hemolysate analysis.
abstract: Investigated were 24 cases of glycogenosis caused by a reduction in liver phosphorylase activity. The intravenous glucagon tolerance test could not discriminate between phosphorylase kinase deficiency [glycogen storage disease (GSD) IX] and phosphorylase deficiency (GSD VI). These two subgroups were distinguished by hemolysate enzyme assays: (1) GSD IX was characterized by a residual phosphorylase kinase activity, a low activation curve for endogenous phosphorylase b and increased amylo-1,6-glucosidase activity. (2) GSD VI was characterized by a normal or increased phosphorylase kinase activity, a slight activation of endogenous phosphorylase b and a normal amylo-1,6-glucosidase activity.
mesh_terms: D002648:Child; D002675:Child, Preschool; D005260:Female; D005934:Glucagon; D006004:Glycogen Debranching Enzyme System / Q000097:blood; D006008:Glycogen Storage Disease / Q000201:enzymology / Q000209:etiology*; D006801:Humans; D007223:Infant; D008099:Liver / Q000201:enzymology*; D008297:Male; D010764:Phosphorylase Kinase / Q000097:blood* / Q000172:deficiency; D010762:Phosphorylase a / Q000097:blood* / Q000378:metabolism; D010763:Phosphorylase b / Q000097:blood* / Q000378:metabolism; D006005:Phosphorylases / Q000097:blood*
chemical_list: D006004:Glycogen Debranching Enzyme System; D005934:Glucagon; D010762:Phosphorylase a; D010763:Phosphorylase b; D006005:Phosphorylases; D010764:Phosphorylase Kinase; C030563:amylo-1,6-glucosidase